Derek Beach and Rasmus Brun Pedersen have written the first practical guide for using process tracing in social science research. The book introduces a more refined definition of what process tracing methods are, differentiating it into three variants, showing the uses and limitations of each. This is followed by chapters developing the underlying logic of process tracing, including how we should understand causal mechanisms in process tracing, and introducing Bayesian logic and how it enables strong within-case inferences to be made in process tracing case studies. The third part of the book develops a set of tools for how the three variants of process tracing methods can be used in research, introducing a set of practical guidelines for each stage of the research process (working with theories, developing empirical tests, working with evidence, and case selection strategies, nesting case studies in mixed-methods designs).